High-frequency electron discharge device



Dec, 26, 195@ B. M. CHARQHIAN 9 3 HIGH-FREQUENCY ELECTRON DISCHARGE DEVICE Filed April 19, 1947 [Q 16 g f g. i

ATTORIVEY Patented Dec, 26, 1950 HIGH-FREQUENCY ELECTRON DISCHARGE DEVICE Eenjamin Malcolm .Charchian, New York, N, $1,,

assigns)! to Federal Telecommunication Laboratories, in New Yorh, N, Y., a corporation of Delaware Application Aprii 19, 1947,, Serial No, 7422,531

8 aims, 1

This invention relates to an ultra high frequency device, and more particularly to the arrangement of an electrode connection of an ultra high frequency discharge device.

An object of the present invention is to reduce the capacity between an electrode of an ultra high frequency device and other circuits.

Another object is to isolate the high frequency output from the plate voltage supply for the anode electrode of an ultra high frequency discharge device.

Another object of the invention is to provide a broad band response.

Another object is to increase the efficiency of ultra high frequency discharge devices.

A further object is to eliminate radiation of high frequency energy from the plate high voltage lead of an ultra-high frequency discharge device.

Other objects will be apparent from the following description.

According to the invention the anode of an ultra high frequency tube is extended beyond the glass envelope of the tube, and inner and outer conductors are mounted concentric therewith.

The anode and inner conductor are so arranged that they overlap a given amount so that a radio frequency zero impedance appears between the ed e of the inner conductor and the opposing surface of the anode thereby preventing the high frequencies from dissipating in the space inside of the inner conductor.

This invention will be described in detail with reference to the accompanying drawing which shows one embodiment of the invention,

Referring to the drawing there is shown an ultra high frequency tube l of the disc seal type having an external anode 2, a cathode 3, and a grid 4 which i mounted on a disc passing a through the envelope of the tube l. The tube 1 is located within a cylindrical conductor 6 and arranged coaxially therewith. A cylindrical conductor l is connected to the cathode 3 and serves as the cathode line. A cylindrical line 8 extends from the grid disc 5 and between the cathode sulator l0, and extends beyond the insulator ill to overlap a portion of the anode extension 9. A plate high voltage lead [2 is positioned within the insulator I8, and is attached to the anode extension 9 for the purpose of connecting the an ode 2 to a plate supply or modulator (not shown) The cathode line 1 and the adjacent portion of the outer conductor 6 form a cathode resonant line l3. The resonant line MA is formed by the outer surface of anode extension 9 and the inner surface of the outer conductor 6. Anode resonant lines MA and MB have different characteristic impedances. The resonant line I413 is formed by the outer surface of inner conductor II and the inner surface of the outer conductor 6. The cathode resonant line I3 may be. tuned by moving the sliding pistons [5 along the major axes of conductors 6 and i. The anode resonant line is tuned by moving along the major axes of conductors 6 and I l, the piston It being adjusted to match the resonant lines MA and HEB. This feature of the two resonant lines gives the device a broad band response.

A cylindrical ring I! is telescopically mounted on the cylindrical line 8 for tuning the grid circuit and additionally tuning the cathode. This may be adjusted through suitable slots I8 in the conductor 6 in any mechanically convenient manher.

The radio frequency energy is removed in the anode resonator M by a suitable line l9 and delivered to the coaxial line 20.

A cylindrical sleeve conductor 2| is slidably mounted on the anode extension 9 and is adjustable so as to change the effective electrical length of the anode extension. This sleeve 2| may be positioned before mounting of the tube I or afterwards through one lower end of conductor l l.

The column 22 between the inner conductor II on one side and the sleeve 2! and a portion of the anode extension 9 on the other side is adjusted to produce a radio frequency short between points 23 and 24 by adjusting the longitudinal distance between the edge 23 of the inner conductor II and the lower edge 25 of the sleeve 2| to an electrical open quarter wave length. This prevents the radio frequency energy from entering into the space inside of the inner conductor II, and for radio frequency considerations is the equivalent of an annular metallic conductor from 23 to 24.

The inner conductor I! may also be made adjustable. A spring socket 21 mounted on the end of the conductor 6 will hold the inner conductor 3 H in place and permit the position of the conductor H to be adjusted longitudinally. The length of the column 22 can then be adjusted by moving the inner conductor I l.

Grid bias is provided by means of the lead 28. The lead 28 extends coaxially through the wave trap 29 and is connected to the disc 5. The wave trap 29 is attached to the outer conductor 6 and prevents the radio frequency from flowing out along lead 28.

While the particular arrangement described functions as an oscillator, the invention can also be used in amplifiers or other electronic circuits of similar construction.

While I have described above the principle of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of my invention as defined in the accompanying claims.

What is claimed is:

1. A high frequency electron discharge device for broad band operation comprising a cathode, a grid, an anode, a cathode cavity resonator connected between said cathode and said grid for applying input signals to said device, an anode cavity resonator for obtaining output signals comprising an extension of said anode and an outer conductor positioned concentrically thereabout coupled to said grid, an intermediate cavity resonator coupled to said anode cavity resonator, said intermediate cavity resonator comprising said outer conductor and an intermediate conductor concentrically positioned between said outer conductor and said anode extension and overlapping said anode extension a length equal to an odd integral number of quarter-wave lengths at the operating frequency of the device whereby radio frequency energy developed in said anode cavity resonator is efiectively blocked from passing between said anode extension and said intermediate conductor.

2. A high frequency electron discharge device for broad band operation comprising a cathode, a grid, and an anode, a lead-out connection for said anode, a cathode cavity resonator connected between said cathode and said grid for applying input signals therebetween, an anode cavity rescnator connected between said anode and said grid for obtaining output signals, shielding means positioned between said lead-out connection and overlapped by said outer conductor, and means to adjust the length of the overlap of said inner conductor by said outer conductor whereby the effective electrical length of the overlap may be adjusted to an odd integral number of quarterwave lengths at the operating frequency of the device.

3. A high frequency electron discharge device according to claim 2 wherein said adjusting means comprises an adjustable conductor connected to the end of said inner conductor distant from said first end.

4. A high frequency electron discharge device according to claim 2 wherein said adjusting means comprises a contact adjustably supporting said outer conductor.

5. A high frequency electron discharge device according to claim 2 wherein said adjusting means comprises an adjustable conductor connected to the end of said inner conductor distant from said first end and a contact adjustably supporting said outer conductor.

6. A high frequency electron discharge device for broad band operation comprising a grid and at least one additional electrode, a lead-out connection for said electrode, a cavity resonator connected between said electrode and said grid, shielding means positioned between said lead-out connection and said cavity resonator, said shielding means comprising an inner conductor and an outer conductor positioned concentrically therearound and spaced therefrom, said inner conductor having one end thereof connected to said electrode and having a portion thereof distant from said end overlapped by said outer conductor, and means to adjust the length of the overlap of said inner conductor by said outer conductor whereby the effective electrical length of the overlap may be adjusted to an odd integral number of quarter-wave lengths at the operating frequency of the device.

7. A high frequency electron discharge device comprising a disc-seal type electron tube having a grid, cathode and anode, an inner conductor and an outer conductor concentrically positioned therearound and spaced therefrom, a cylindrical member having one end thereof connected to said anode, an adjustable conductive sleeve telescopically mounted on said member and extending beyond the other end thereof, said sleeve and a portion of said member concentrically overlapped by said inner conductor, said sleeve extending within said inner conductor a distance so that the length of overlap of said inner conductor over said sleeve and said member equals an odd integral number of quarter-wave lengths at the operating frequency of said device, and an adjustable piston positioned between said inner conductor and said outer conductor for tuning said device to resonate at a particular frequency.

8. A high frequency electron discharge device as claimed in claim 7, further comprising a contact for adjustably supporting said inner conductor at an end distant from said member and said sleeve, whereby the overlap of said inner conductor over said member and said sleeve may be adjusted to a distance equal to an odd integral number of quarter-wave lengths at the operating frequency of said device.

BENJAMIN MALCOLM CHARCHIAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,272,211 Kohler Feb. 10, 1942 2,408,355 Turner Sept. 24, 1946 2,443,907 Gurewitsch June 22, 1948 

